This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SPECIMEN PREPARATION, PRESERVATION AND STAINING TECHNOLOGIES FOR MAPPING PROTEINS, CELLULAR COMPLEXES, PATHWAYS AND THE SUPRAMOLECULAR ORGANIZATION OF TISSUES USING MULTIPLE LABELS AND MULTISCALE IMAGING. Our efforts in this area are focused on developing technologies to enable simultaneous imaging of proteins and macromolecular complexes using multiple labels and multiscale microscopies. These approaches include (1) new metal chelating derivatives of diaminobenzidine that can be used for simultaneous multi-protein EM labeling using electron energy loss spectroscopy (EELS);(2) enhancing the sensitivity of our repertoire of fluorescent compounds used for multiscale imaging;and (3) improved preservation of probe fluorescence, antigenicity, and cellular ultrastructure in resin-embedded samples to facilitate new imaging applications. In addition, we are working to extend the usefulness of fluorescent nanoparticles (e.g., quantum dots) as probes for multiscale, multimodal imaging.